Time-resolved analysis of intramolecular electronic energy transfer in methylenes-linked naphthalene–anthracene compounds in solution and in stretched polymer films

2003 ◽  
Vol 102-103 ◽  
pp. 278-282 ◽  
Author(s):  
Shammai Speiser ◽  
Miki Hasegawa ◽  
Shigendo Enomoto ◽  
Toshihiko Hoshi ◽  
Katsuyuki Igarashi ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Polymer Films ◽  
Electronic Energy ◽  
Time Resolved ◽  
Electronic Energy Transfer

Time-resolved analysis of intramolecular electronic energy transfer in methylenes-linked naphthalene–anthracene compounds

2000 ◽  
Vol 323 (1-2) ◽  
pp. 117-124 ◽  
Author(s):  
Yoshinobu Nishimura ◽  
Akira Yasuda ◽  
Shammai Speiser ◽  
Iwao Yamazaki
Keyword(s):  
Energy Transfer ◽  
Electronic Energy ◽  
Time Resolved ◽  
Electronic Energy Transfer

Interactions of dyes with wool. Spectral and photochemical studies of fluorescent whitening agents

1977 ◽  
Vol 30 (1) ◽  
pp. 87 ◽  
Author(s):  
IH Leaver
Keyword(s):  
Energy Transfer ◽  
Polymer Films ◽  
Spectral Study ◽  
Emission Spectra ◽  
Electronic Energy ◽  
Fluorescence Excitation ◽  
Fluorescence Depolarization ◽  
Electronic Energy Transfer ◽  
Fluorescent Whitening Agents ◽  
Photochemical Behaviour

A spectral study has been made of the interactions of four types of fluorescent whitening agents with wool. Fluorescence excitation and emission spectra have been measured in single wool fibres, and are compared with the corresponding spectra in solution and in polymer films. The polarity of the environment has a pronounced effect on the fluorescence properties of the whiteners in solution, but generally has little effect in rigid media. The emission spectra in wool are found to be strongly influenced by the concentration of whitener in the fibre. This heterogeneity of the fluorescence is attributed both to aggregation of the whitener and to changes in the polarity of its micro-environment in the fibre. The results of fluorescence depolarization studies indicate that electronic energy transfer between whitener molecules occurs efficiently at the concentrations normally used for whitening wool. Critical transfer distances and concentrations have been determined for the various whiteners, and are compared with the values predicted by Forster's theory of dipole-dipole transfer. The photochemical behaviour of the fluorescent whiteners in wool has been examined, and the effects of oxygen and water on the fading rates are discussed.

The Dynamics of Electronic Energy Transfer in Novel Multiporphyrin Functionalized Dendrimers:  A Time-Resolved Fluorescence Anisotropy Study

2000 ◽  
Vol 104 (12) ◽  
pp. 2596-2606 ◽  
Author(s):  
Kenneth P. Ghiggino ◽  
Joost N. H. Reek ◽  
Maxwell J. Crossley ◽  
Anton W. Bosman ◽  
Albert P. H. J. Schenning ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Anisotropy ◽  
Electronic Energy ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Electronic Energy Transfer

Sub-picosecond time-resolved intramolecular electronic energy transfer in bichromophoric rhodamine dyes in solution

1988 ◽  
Vol 122 (3) ◽  
pp. 431-442 ◽  
Author(s):  
N.P. Ernsting ◽  
M. Kaschke ◽  
J. Kleinschmidt ◽  
K.H. Drexhage ◽  
V. Huth
Keyword(s):  
Energy Transfer ◽  
Electronic Energy ◽  
Time Resolved ◽  
Electronic Energy Transfer ◽  
Rhodamine Dyes

Electronic Energy Transfer from Excitons Confined in Silicon Nanocrystals to Molecular Oxygen

2003 ◽  
Vol 770 ◽  
Author(s):  
E. Gross ◽  
D. Kovalev ◽  
N. Künzner ◽  
J. Diener ◽  
F. Koch ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Molecular Oxygen ◽  
Elevated Temperatures ◽  
Electronic Energy ◽  
Time Resolved ◽  
Electronic Energy Transfer ◽  
Si Nanocrystals ◽  
Developed Surface ◽  
Quenching Efficiency ◽  
Resonant Electron

AbstractWe report on efficient electronic energy transfer from excitons confined in silicon (Si) nanocrystals to molecular oxygen (MO). The remarkable photosensitizing properties of Si nanocrystal assemblies result from a broad energy spectrum of photoexcited excitons, a long triplet exciton lifetime and a highly developed surface area. Quenching of photoluminescence (PL) of Si nanocrystals by MO physisorbed on their surface is found to be most efficient when the energy of excitons coincides with the triplet-singlet splitting energy of oxygen molecules. Spectroscopic analysis of the quenched PL spectrum evidences that energy transfer is accompanied by multi-phonon emission. From time-resolved measurements the characteristic time of energy transfer is found to be in the range of microseconds. The dependence of PL quenching efficiency on the surface termination of nanocrystals is consistent with short-range resonant electron exchange mechanism of energy transfer. The energy transfer to oxygen molecules in the gaseous phase at elevated temperatures is demonstrated.

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